SE520045C2 - Coding Patterns - Google Patents

Abstract

A product is provided with a coding pattern, which codes position information in the form of coordinates for a plurality of points on the product with the aid of a plurality of marks belonging to each point. The marks have a first parameter which varies for coding of the position information. The marks additionally have a 10 second parameter which varies for coding of further in formation in the coding pattern. A method and a device for coding of the coding pattern and a method and a device for decoding of the coding pattern are also described. 15

Description

25 30 35 520 045 2 in relation to the nominal position.

The dots can, for example, have four possible locations, one on each of the four raster lines starting from the point of intersection, the four different locations encoding four different values. The coordinates of a point are coded using a number of dots, for example 6 * 6 dots.

However, each dot contributes to the coding of the coordinates for several points. If a sensor first reads 6 * 6 dots and then moves a dot distance to the side or vertically, the sensor will read dots that encode the coordinates of a new point. This type of pattern where an arbitrary sub-surface of a predetermined size defines a position is called "floating" in this application.

With the help of the pattern in the above-mentioned WO 01/26032, coordinates for a very large number of points can be coded, theoretically 4% points if each point is coded with 6 * 6 dots. All these points can be said to form an imaginary surface. WO Ol / 48685, which is also assigned to the applicant for the present invention, describes how such an imaginary surface can be used for information management. More specifically, different sub-areas on the imaginary surface are dedicated to different types of information management. You can then control how information that is registered digitally is to be handled by providing data with position coding patterns that correspond to different sub-areas on the imaginary surface. A first base can, for example, be provided with a position coding pattern which means that information written on the position coding pattern and registered digitally by the pen is sent to a predetermined computer for storage therein. Correspondingly, another document can be provided with a position coding pattern which means that information registered digitally with the aid of this position coding pattern is sent as an e-mail to an address specified by the user on the document.

It appears from the above that there is an interest in the total position coding pattern being able to code coordinates for as large a number of points as possible. This applies not only to the position coding pattern described above but to all coding patterns that can be used for information management. Examples of other coding patterns are found in US-A-5,168,147 and US-A-5,245,165.

One possibility to encode coordinates for more points could be to increase the number of values that each selection can encode. In the above example, each dot would be allowed to have more than four different possible locations for encoding more than four different values. However, the more different placements you allow, the more difficult it will be to decode the pattern correctly.

WO Ol / 48685 further describes that the pen which registers the position coding pattern can store various digital templates or page layouts, which define how the information on physical data with position coding patterns is to be interpreted. For example, a template may specify that a document with the corresponding position coding pattern has a first field intended for a message, a second field intended for an e-mail address to be ICR-interpreted (ICR = Intelligent Character Recognition), and a third field , which is a send box that the user ticks to initiate the sending of registered information.

As further described in WO Ol / 48685, the position coding pattern can be arranged in different ways on the physical substrate. According to a first alternative, the position coding pattern on the substrate can be continuous, which means that it corresponds to a continuous area on the imaginary surface. The unit that is to interpret and process the digital information registered from the base must then know the layout of the base, ie which fields are on the base and where these are located. If many different layouts are allowed, which is of course desirable, a large amount of information must be stored so that it is accessible to the device that is to process the information. This is especially a problem if the processing unit has limited memory capacity and / or it is cumbersome to change the information once it has been stored. This may be the case, for example, if the treatment unit consists of a portable user unit, such as the pen in WO Ol / 48685.

According to a second alternative, the position coding pattern on the substrate can correspond to several separate sub-areas on the imaginary surface so that a discontinuous layout is obtained. The position coding pattern in the first field may then correspond, for example, to a first subarea on the imaginary surface dedicated to message information, the position coding pattern in the second field correspond to a second subarea dedicated to address information to be ICR processed and the position coding the pattern in the third field corresponds to a sub-area dedicated to transmission boxes. In this case, therefore, the placement of the fields on the substrate is not related to the placement of the corresponding sub-areas on the imaginary surface. With this alternative, the unit that is to interpret and process the digital information from the data needs to store a small amount of information because it only needs to know the coordinates of the different fields.

In some situations, however, the continuous layout is still preferable. If the pattern is of the floating type, positions will not be able to be defined in a boundary area between two different fields in the discontinuous layout because the dots in the boundary area do not encode coordinates of adjacent points on the imaginary surface. One way to solve this problem is to have no position coding pattern in the boundary area so that points belonging to one or the other field can be detected unambiguously. Such boundary areas without position coding patterns may be undesirable, especially when the product is small. Therefore, it would be advantageous to be able to use page layouts or templates with a continuous position coding pattern without the unit that is to process the information having to store the specific layout for each conceivable layout on the physical substrate.

This is particularly desirable when different parties are to be allowed to produce data with different layouts at the same time as the digital information registered from these data can be processed in one or a few central units whose layout databases cannot be updated every time a party wants to use a new, undefined layout or in user units with limited memory capacity and where it is difficult to update the layout database after manufacture when the user has received the user unit.

SUMMARY OF THE INVENTION An object of the present invention is thus to fully or partially solve the above problems.

This object is achieved by means of a product according to claim 1, a coding method according to claim 13, a coding device according to claim 21, a decoding method according to claim 27, a decoding device according to claim 34.

According to a first aspect of the invention, this thus relates to a product which is provided with a coding pattern, which encodes position information in the form of coordinates of a plurality of points on the product by means of a plurality of markings belonging to each point, which have a first parameter which varies for encoding the position information. The markings further have a second parameter that varies for coding additional information in the coding pattern.

Thus, instead of encoding additional information in the encoding pattern using the same parameter, such as the location in the example mentioned in the introduction, another parameter, such as color or size, is used to encode the additional information. The additional information will then be easier to detect with a sensor, since the information is now coded in two different "dimensions". This reduces the risk of error detection.

L L - @. ZcaL-zciieav ss i2; 2 :: 2-c§ ~; f ~ t “ëw:« «» f 10 15 20 25 30 35 520 045 6 the parameter can thus also be optically detectable. The parameters can typically refer to the shape, color, grayscale, size, angular position, location and / or degree of filling of the markings.

The coding pattern may be of the type mentioned in the introduction described in WO 01/26032, but the principles of the invention are also applicable to other position coding patterns which are built up of a plurality of discrete markings, each of which can encode at least two different values.

In one embodiment, the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. A preferred combination is location and size, as these parameters are comparatively easy to detect.

The additional information may be additional position information, the variation in the second parameter making it possible to encode at least two additional values for each selection. In the initially related case where a selection encodes four different values using four different locations, one would by varying a second parameter of the selection between two different values, for example the parameter "size" between the values "small" and "large" , be able to encode eight different values for each mark, which would thus enable coding of coordinates for 8% points in the previous example where each point was coded with 6 * 6 marks.

The additional information may alternatively be other information than position information and it may then form a second information layer, the position information constituting the first information layer. The second information layer may, for example, contain elevation information related to positions on a map encoded with the position information.

It is further conceivable to encode additional information in the second information layer with a very high redundancy so that when a certain amount of position information has been recorded digitally by means of the position coding pattern, the additional information contained in the second information layer also has a very high redundancy. probability registered. The additional information could, for example, be an address to which the information recorded digitally by means of the position coding pattern is to be sent.

The additional information can further be used to define at least two different areas or fields on the coding pattern. The ranges can be defined by giving the second parameter a value in one range and another value in the other range. This ability to define areas in the coding pattern so that it can be deduced from the digitally registered information with which area the information is associated can be used to reduce the initially mentioned problem of storing page layout information. A party who wants to create a new layout, for example with an address field at the top of a page instead of at the bottom of a page, could, with the help of the second parameter, be able to define an address field at the top of a page with a continuous position coding pattern. This presupposes, of course, that in the unit that is to interpret the digitally registered information, it is defined that information with a certain value on the second parameter is to be interpreted as address information. The technique of using the second parameter to paint digitally detectable areas on the position coding pattern provides the same advantages in terms of the need for information storage as the use of side lots with a discontinuous position coding pattern.

The additional information can alternatively define whether a predetermined area in the coding pattern is activated or not. A layout can then include several areas placed in different places with the same function, for example several address fields or several transmission boxes. A party who is to use the layout can then, with the aid of the second parameter, encode additional information in the coding pattern, which additional information indicates whether the corresponding points belong to an activated area or not.

The unit that is to process the registered information then knows, for example, whether coordinates registered from a transmission box area are to be interpreted as a transmission instruction or, if the transmission box in question is not activated, as another type of predefined information.

The additional information can, as stated above, define how coordinates registered from the at least two different areas are to be processed. The invention could thus be described as a product with a coding pattern, which encodes coordinates of a plurality of points on the product by varying a first parameter of a plurality of markings belonging to each point, which is intended for digital registration of information written on the coding pattern, and which comprises at least a first and a second area, wherein information recorded digitally is intended to be processed in different ways depending on which of said areas the information is recorded and wherein the first and the second area are encoded in the coding pattern by varying a second parameter of the markings.

The coding pattern may further be divided into a plurality of cells, each of which comprises at least two markings, the additional information consisting of a cell value which is coded by the at least two markings for each cell. In this way, more different types of areas can be coded using the second parameter. For example, if you divide the coding pattern into cells of two selections and each selection can have two different values for the second parameter, up to four different types of ranges can be coded with different cell values. 10 15 20 25 30 35 520 045 9 The cells may include fewer markings than the plurality of markings associated with each point required to encode the coordinates of a point. If the additional information is used to define areas, for example, a smaller number of cell values is needed. Then the cells can be made rather small, so that the markings that define the coordinates of a point define several cells. This makes the coding more robust and error decodings are more easily detected.

To further increase the robustness of the coding, each tag may have one of at least two predetermined values for the second parameter and each cell may include at least one tag with each of the predetermined values. Since in this case there is always a marking with every possible value, the markings can be compared with each other during decoding. This makes it easier to determine the value of a mark that has been distorted during registration during decoding.

If a first and a second area of a coding pattern are defined with different values of the second parameter for the markings or with different cell values, problems can arise in a boundary area between the first and the second area. If the tip of the pen that the user writes on the substrate and the sensor that registers the position coding pattern are offset from each other, it may mean that the user writes with the pen tip in the first area, but the sensor registers the coding pattern in the second area, or vice versa. One way of at least partially solving the problem is to allow the boundary region to include cells with the first cell value and cells with the second cell value, i.e. a mixture of cells with different cell values. The mixture may indicate to the entity that is to process the information that the registration of digital information is done in a border area, whereby the processing unit may use information registered immediately before and / or immediately after 10 15 20 25 30 35 520 045 10 to determine if the information in question must be interpreted as belonging to one or the other area.

According to a second aspect of the invention, it relates to a method in an encoding device for providing an encoding pattern which encodes position information in the form of coordinates for a plurality of points by means of a plurality of markings associated with each point, comprising the steps of encoding the position information. assigning each mark in a digital representation of the markings in the coding pattern one of at least two predetermined values for a first parameter and assigning each marking one of at least two predetermined values for a second parameter for coding additional information in the coding pattern.

The method can be implemented by means of a computer program, which may be stored in a memory in the coding device or in some other unit from which it can be made available to the coding device.

According to a third aspect of the invention, it relates to a device for coding a coding pattern, which encodes position information in the form of coordinates of a plurality of points on a surface by means of a plurality of markings belonging to each point, which device comprises processing means for determining a value for a first parameter for each selection and a value for a second parameter for each selection and a memory for storing the values of the selections for the first and second parameters.

The coding device may be, for example, a suitably programmed computer, the processing means being a processor, or a specially adapted hardware of some kind, where the processing means is realized with, for example, an ASIC or an FPGA or with some arrangement of digital and / or analog circuits.

According to a fourth aspect of the invention, this relates to a method in a decoding device, of a coding pattern, which encodes position information in the form of coordinates for a plurality of points on a product by means of a plurality of markings associated with each item, including the steps of receiving a digital representation of the coding pattern, decoding the position information using the value of the first parameter for at least some of the markings in the digital representation, and decoding further information from the coding pattern on basis of the value of a second parameter for at least some of the markings in the digital representation.

The method can be implemented by means of a computer program which can be stored in, for example, a memory in the decoding device or in some other unit from which it can be made available to the decoding device.

According to a fifth aspect of the invention, it relates to a device for decoding a coding pattern which encodes position information in the form of coordinates of a plurality of points on a product by means of a plurality of markings belonging to each point, which device comprises processing means which are arranged to receive a digital representation of the coding pattern, to decode the position information by means of the value of the first parameter for at least some of the markings in the digital representation. The processing means are further arranged to decode further information from the coding pattern on the basis of the value of a second parameter for at least some of the markings in the digital representation.

The decoding device may be, for example, a computer-based unit, the processing means being a suitably programmed processor, or a specially adapted hardware of some kind, where the processing means is realized with, for example, an ASIC or an FPGA or with some arrangement of digital and / or analog circuits. The decoder may be a stand-alone unit, such as a handheld user unit, or be built into a fax, scanner or similar apparatus.

It should be noted that the coding device and the decoding device may have means for performing each of the steps in the coding and decoding method described above. The means may, for example, consist of program code for performing the various steps.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described by way of embodiment with reference to the accompanying drawings, in which: Fig. 1 schematically shows a system for information handling, which system uses a coding pattern for controlling the information handling.

Fig. 2 shows an example of coding of a known position coding pattern by means of only a first parameter.

Fig. 3 shows an example of coding of a coding pattern by means of a first and a second parameter.

Fig. 4 shows division into cells of a coding pattern of the same type as in Fig. 3.

Fig. 5 shows an example of a page layout.

Fig. 6 schematically shows an example of encoding additional information.

Fig. 7 schematically shows a coding device.

Fig. 8 is a flow chart showing an example of how coding of a coding pattern can be performed.

Fig. 9 schematically shows a decoding device.

Fig. 10 is a flow chart showing an example of how decoding of a coding pattern can be performed.

Description of exemplary embodiments Fig. 1 schematically shows a system for information management, in which the present invention can be used. The system comprises a substrate 1 in the form of a paper, a user unit 2 and an external unit 3.

The paper is provided with a coding pattern 4 of which only a small part is schematically indicated in an enlarged condition. User unit 2 can be used to write on the paper 1 and to simultaneously register what is written in digital form. The digitally registered information can be processed in the user unit 2 and / or the external unit 3, to which it can be sent automatically (online) or on a signal from the user.

The position information in the coding pattern 4 can be coded in the manner described in WO 01/26033. As shown in Fig. 2, the position information is then coded by means of markings 20, which here have the shape of dots. Each dot has a nominal position 21 which is given by the point of intersection between the lines 22 in a grid. The raster can be virtual, but is shown here for the sake of brevity using dashed lines. Each dot may be in one of four predetermined locations relative to the nominal position, namely on a grid line above, to the right, below or to the left of the nominal position. Fig. 2 shows examples of these different placements. Depending on the location, for example, the dot may encode the bit pairs (0.0; 0.1; 1.0; and 1.1). The location is thus an example of a first parameter for coding position information in a coding pattern.

In the coding pattern 4 in Fig. 1, additional information is coded in addition to the position information. A second parameter of the dots is used for the coding of the additional information. Fig. 3 shows an example of this. Each dot now has, in addition to a placement, also a predetermined size value. In this example, each dot has either the size value "large" (see for example "small". In this way, each dot can code 23, ie 8 dot 31) or the size value (see for example dot 32). different values, which enables coding of a larger pattern than before, if the second parameter is used for position information.

In this example, however, the second parameter is used to encode information other than position information. For this purpose and to increase the robustness of the coding, the coding pattern, as schematically shown in Fig. 4, is divided into cells 40. The cells are normally not marked on the substrate on which the coding pattern is located but are virtual cells. For the sake of clarity, however, they are marked in Fig. 4 with dashed lines 41.

However, the grid lines are not shown in Fig. 4.

In this example, each cell contains four dots.

Cells with a different number of dots can of course be used. The cells also do not have to be square as in this example, but can have other shapes, such as rectangular, triangular or hexagonal. The preferred shape can be affected by the design of the grid for the dots. Not all cells need to be the same size, only their extent can be determined.

Furthermore, as shown in Fig. 4, the cells do not overlap each other, but are fixed in relation to the pattern, which makes their location easy to determine as soon as the position information in the coding pattern has been decoded. In this example, the coordinates of each point are coded with 6 * 6 dots. Furthermore, the coding is "floating", which means that each sub-area in the coding pattern that comprises 6 * 6 dots encodes coordinates for a unique point. The coordinates are defined for the upper left dot in each 6 * 6 sub-area. This fact can be used to determine the location of the cells. If the cells are laid out starting in the upper left corner, which has the coordinates x = 0 and y = 0, on the total position coding pattern, the upper left corner of each cell will have an even x-coordinate and an even y-coordinate , which can thus be used to determine the location of the cells on any part of the coding pattern.

Furthermore, to increase the robustness of the coding, each cell in this example contains either only small dots or two large dots and two small dots. The two large dots can be selected from the four dots in (41 / (2! * 2!)) = 6 different ways. With the aid of the second parameter it is thus possible in this case to encode 1 + 6 = 7 10 l5 20 25 30 35 520 045 15 different cell values, whereby the cells with only small dots are suitably used to indicate "background" where no further information is encoded . Other cell values can represent different forms of additional information.

Assume that in the user unit 2 in Fig. 1 there are stored, in digital form, a plurality of page layouts which are based on continuous position coding pattern. Each page layout can be defined with two coordinate pairs defining the extent of the page, for example page, and two coordinate pairs for each of the areas or fields defined on the page. In addition, each of the fields is provided with an indication of the field type or the function of the field, ie how information digitally registered from these fields is to be interpreted and / or processed.

Fig. 5 shows an example of a physical page 50 which is intended to be used for sending an e-mail and which corresponds to a digital page layout stored in the user unit. On the page there is a field 51, which is intended for graphic information, for example a handwritten message. At the bottom of the page there is also a field 52, which is intended for address information to be ICR-interpreted.

Finally, there is a field or box 53 that is intended to be filled in by the user when he or she wants to send the e-mail. Parts of the page outside the marked fields are not intended for registration of information.

The entire page is provided with a continuous coding pattern (not shown).

A user can fill in relevant information on page 50 because the different fields are marked on the page in a way that is understandable to the user. The information that is digitally registered from the page with the aid of the user unit 2 consists of digital representations of sub-areas of the coding pattern. If now the coding pattern would only contain position information, as is the case in Fig. 2, the digitally registered information 10 15 20 25 30 35 520 045 16 would not contain any information about from which field the information is registered. However, since the user unit contains the digital description of the page layout, the user unit can decide from which field the information is registered and thus how it is to be processed and / or interpreted.

Now assume, however, that a party wants a layout with the address field 52 and the send box 53 at the top of the page instead of at the bottom and that such a page layout is not predefined in the user unit 2. It is then not enough to change the layout on the physical page. or a corresponding digital layout is created so that the user unit can interpret the digitally registered information and process it correctly. If only the layout is changed on the physical side and the same position coding pattern is used on it, the user unit will interpret the digitally registered information by means of the digital layout corresponding to Fig. 5. If the user then writes an e-mail address at the top of the page in the address field marked on the physical page, the user unit will still only interpret the information as message information because according to the digital layout, the information comes from the message field 51. In the interpretation it is the digitally stored page layout that applies and it can be difficult to change for a party who wants a different layout than the ones that are predefined.

One way to solve this problem is to define in one and the same digital layout several alternative fields, for example an address field at the bottom of the page and one at the top of the page and to use the additional information coded in the coding pattern in Fig. 3 to mark if a field is activated or not. On the physical side, fields that are to be activated with a first cell value and fields that are not to be activated with a second cell value are coded. Alternatively, active fields can be coded with a first value on the second parameter and inactive fields can be coded with a second value on the second parameter, whereby for example all markings in an active field are made large to mark that the field is active. As a further example, the values of the markings can vary in a predetermined way in an active field, for example every other large and every other small, while all markings in an inactive field have one and the same value.

A coding of the type described above can easily be achieved in the production of the physical side. In addition, information on how active / inactive fields are coded only needs to be added to the user unit.

An alternative solution to the above problem is to define different types of fields or areas from which registered digital information is to be interpreted and / or processed in different ways. The different field types can be coded using different cell values. The unit that is to process the digitally registered information then only needs to have a single page layout with a continuous position coding pattern and a table of the meaning of the various cell values. A party who wants to create a physical page with its own layout can then "paint" the layout using the different cell values.

If the user unit 2 has a pen tip and a sensor which are offset relative to each other, problems can, as already mentioned, arise in a boundary area between two fields or areas by the pen tip pointing to a first field while the sensor registers the coding pattern in a second field. The problem can be at least partially remedied by coding the cell values in the boundary area in a specific way so that the processing unit can determine that the registered coordinates originate from a boundary area and should therefore be treated in a special way.

One way to code the boundary area is to mix cell values from the two adjacent fields in a chess pattern. Another way is to let the cell values gradually shift from the cell value of one field to the cell value of the other field so that the processing unit can thereby determine where in the boundary area the coordinates were registered. Of course, you can create more complicated layouts by mixing cells with two or more different cell values in more advanced ways.

An example of a more advanced coding is shown in Fig. 6. Assume that the sensor registers 8 * 8 markings, that cells with 2 * 2 markings are used and that the sensor sees 4 * 4 cells, as shown in the middle of Fig. 6, where the cells as the sensor ser is denoted by 60. In a border area, however, one is more interested in the additional information available at the pen tip than the additional information that the sensor sees. You can then let each of the cells within a 4 * 2 cell range encode the cell value of a cell that is at the same distance from the sensor as the pen tip does in eight different directions. In Fig. 6, this is shown schematically with surrounding cells 61. The cell value of each cell 60 and 61 is marked in the cell and dashed lines 62 show associated cells. It then appears that the eight top cells 60 and the eight bottom cells 60 which the sensor sees in this case encode the values of the surrounding eight cells 61. By decoding the additional information in the coding pattern which the sensor registers, one can thus determine the additional information. which is present in the coding pattern at the pen tip for different rotations of the pen, whereby it becomes possible, for example, to determine whether the pen tip is in an activated field or not.

The coding of the coding pattern can take place in a coding device, for example at a party who wants to create a page with a special layout for information handling. An example of a coding device is shown schematically in Fig. 7.

The coding device, which can for instance be realized with an ordinary personal computer, comprises a processor unit 70 which in addition to the processor 71 itself comprises a working memory 72 and a program memory 73 which stores a program for producing the coding pattern. The coding device further comprises input means 74, which enables a user to input information about a desired page layout to the processor unit. The input means 74 may be, for example, a keyboard or a mouse or any corresponding input device normally used in conjunction with a computer. Furthermore, a unit 75 can be connected to the coding device, which on the basis of the digital representation of the coding pattern applies the coding pattern to a product. The unit may, for example, consist of a printer which prints the coding pattern on a paper or some form of printing device.

In the following, it will be described how the coding is carried out with reference to the flow chart in Fig. 8.

In a first step 80, the processor receives an indication of which coordinate area to coordinate. The indication can come as a direct or processed input signal from the user, who, for example, selects one of several page layouts or templates. The extent of a template or layout can be defined using a coordinate pair that defines the upper left corner of the template, as well as a width and a height on the page. If these values are not stored for the template, they can be given directly by the user.

In connection with this step, space is allocated in the working memory 72 for storing a digital representation of the coding pattern. For each selection included in the coding pattern, the processor then calculates in step 81 a value for a first parameter, which in this example is the location of the selection, according to a predetermined algorithm. How such an algorithm can be constructed is stated in the above-mentioned WO Ol / 26033. The value of the first parameter for each selection is stored in a first matrix in the working memory 72. The value can for example be given as a number between 0 and 3, where 0 means that the mark is offset to the right from its nominal position, 1 that it is offset upwards, 2 that it is offset to the left and 3 that it is offset downwards.

Thereafter, the processor 71 receives an indication of the extent of at least one field to be marked or activated by utilizing the second parameter, step 10 15 20 25 30 35 520 045 20 82. This indication may, for example, come in the form of a direct or processed input signal from the user, the field being described by means of a coordinate pair which defines the upper left corner of the field, the width and height of the field calculated in number of cells and the cell value or cell values to be defined in the field. On the basis of the input signal, the processor determines a second matrix which defines the cell values for the whole template and which constitutes the input signal for the next step in the coding. In the next step, on the basis of the second matrix and in accordance with a predetermined algorithm, it also determines a value for a second parameter for each of the selections, step 83, and stores these calculated values in the memory. More specifically, the processor determines a third matrix having the same size as the first matrix, assigning each mark to the value zero or four, where zero indicates small dot and four large dot. The algorithm for calculating the value of the second parameter can be determined by the person skilled in the art based on the description above of how the second parameter can be used. Finally, the first and third matrices are added together by adding the values in the same place so that a fourth matrix is formed where each element has a value between zero and seven. Each element corresponds to a mark in the pattern and defines its position and size as follows: = small dot, offset to the right = small dot, offset upwards = small dot, offset to the left = small dot, offset downward large dot, offset to the right = large dot, offset up = large dot, offset to the left fl öïUlvlë-LANI- * O ll = large dot, offset down When coding is complete, the coding pattern can be printed with the printer 75 if desired. The fourth matrix can be sent to, for example, a program that generates a PostScript file for direct printing on a printer. Fig. 9 shows an example of how the user unit 2 in Fig. 1, which can be used as a decoding device, can be realized. It comprises a housing 91, which is shaped approximately like a pen. There is an opening 92 in the short end of the housing. The short end is intended to abut or be kept at a small distance from the surface from which the coding pattern 4 is to be registered.

The housing mainly houses an optics part, an electronics part and a power supply.

The optical part comprises at least one LED 93 for illuminating the surface to be imaged and a light-sensitive area sensor 94, for example a CCD or CMOS sensor, for detecting a two-dimensional image. Optionally, the device may additionally contain an optical system, such as a mirror and / or lens system. The LED may be an infrared LED and the sensor may be sensitive to infrared light.

The power supply to the device is obtained from a battery 95 which is mounted in a separate compartment in the housing.

It is also conceivable to provide the power supply via a cable from an external power source (not shown).

The electronic part contains a processor unit 96 with a processor which is programmed to read images from the sensor and decode the coding pattern in these images, as well as working memory and program memory. The processor may further be programmed to perform certain operations on the basis of the decoded information. For example, the processor may send information to a specific address included in the decoded information as a result of interpreting and processing the decoded information.

Alternatively, the processor may only forward the decoded information to another device, for example the external device 3 in Fig. 1, for interpretation and processing of the information.

The device further comprises in this embodiment a pen tip 97, with the aid of which one can write ordinary dye-based writing a basis from which the coding pattern is to be registered. The pen tip 97 can be folded in and out so that the user can control whether it is to be used or not. In some applications, the device need not have a pen tip at all.

Preferably, the dye-based writing is of such a type that it is transparent to infrared light and the markings are absorbent to infrared light. By using an LED that emits infrared light and a sensor that is sensitive to infrared light, the sensing of the pattern takes place without the above-mentioned writing interfering with the pattern.

The device may further comprise buttons 98 by means of which the device is activated and controlled. It also has a transceiver 99 for wireless transmission, for example with IR light, radio waves or ultrasound, of information to and from the device. The device may further comprise a display 900 for displaying registered and / or processed information.

The device may be divided into different physical envelopes, a first envelope containing components necessary to record images of the coding pattern and to transmit these to components contained in a second envelope and which decode the coding pattern in the registered the pictures.

In the following, an example will now be described of how the decoding of the coding pattern can take place with reference to Fig. 10.

In a first step 100, the processor 96 in the user unit 2 receives a digital representation of the coding pattern registered by the sensor 94 locally at the end of the user unit. The processor then decodes in step 101 the position information in the coding pattern by identifying the marks in the digital representation, determining the virtual grid and the position of the marks relative thereto, and calculating the coordinates of each point based on the position of the marks in accordance with a predetermined algorithm. A more detailed description of how the position information can be decoded can be found in WO O1 / 26033.

When the position information has been decoded, the processor in step 102 determines the location of the cells using the coordinates. The processor can then determine the cell value of each cell by determining the size of the markings in the digital representation. Since it is a given that each cell should contain two small and two large markings or only four small markings, the processor can relatively easily determine which markings are small and which are large by comparing the sizes of the markings with each other. Once the sizes of the different markings have been determined, the cell value is easy to determine, for example using a table, step 103. The processor may make an estimate of how safe the cell value is based on how safe the size determination is for the markings in the cell in question.

Of course, the cell values can be determined in other ways. An alternative is to determine the size of each marking and, by comparison with a predetermined or adaptively changeable size distribution, which reflects that the markings are registered in different perspectives and with different lighting, to determine the probability that each marking is large or small. By multiplying the probabilities for different combinations of small and large selections, the processor can determine the cell value that has the highest probability.

Once the processor has determined the cell value of a desired number of the cells visible in the digital representation it has received, the processor can perform an evaluation step 104 in which the cell values for several cells are compared and any estimated or calculated probabilities for the cell values are corrected on basis of the comparison. If the neighboring cells of a current cell have the same cell value as the current cell, the processor can, for example, increase the estimated / calculated probability that the current cell has this cell value. If, on the other hand, several neighboring cells have a different cell value than the cell in question, this may lead to a decrease in the probability of the cell value of the cell in question. In the evaluation step, any information about the distribution of cell values between the cells can also be taken into account.

When the processor has finally determined which cell or values are encoded by the encoding pattern in the current digital representation of the encoding pattern, the processor can either interpret and process the position information itself, i.e. the coordinates, on the basis of the decoded additional information, i.e. the cell values, or send the decoded information to another unit for interpretation and processing.

Alternative embodiments In the examples above, a position coding pattern is used in which the position information is coded by means of the location of the markings and further information is coded by means of the size of the markings. Of course, both position information and the additional information can be coded using parameters other than those exemplified here. Alternatively, the shape of a selection can be used as a parameter. The markings may, for example, have different values based on whether they are circular, triangular, rectangular, star-shaped, elliptical, hexagonal or shaped in any other detectable shape.

However, in order to be able to detect different shapes in different perspectives and different lighting, a sensor with a relatively high resolution may be required. As an additional alternative, the color of the mark can be used so that the value of the mark depends on the color. For this purpose, however, a color sensor or lighting with light of different wavelengths is required.

The principle of using a second parameter to encode the additional information can also be used for position coding patterns with a fundamentally different structure. For example, the position coding pattern need not be fluid. Furthermore, in the examples described above, the markings are in the form of circular dots. Of course, markings of other shapes may be used, such as triangular, square, elliptical, rectangular, or hexagonal dots.

In the examples described above, all cells have two large and two small dots or four small dots for encoding seven different cell values. Of course, one can have smaller or larger cells with fewer or more cell values encoded with other combinations of values of the second parameter.

In the example above, the additional information is coded using a second parameter. However, it would also be possible to encode the additional information directly in the position information itself by encoding the same position in two or more different ways depending on the value of the additional information. This can be done, for example, as follows. The position coding pattern in WO Ol / 26032 is based on a bit sequence which has the property that if one takes a sub-sequence with a predetermined number of bits from the bit sequence, this sub-sequence has a unambiguously determined place in the bit sequence.

This property also applies when connecting the beginning and end of the sequence, which can thus be considered as a ring. When coding positions in, for example, horizontal direction, the bit sequences are written repeatedly in columns in a vertical direction. The bit sequences in different columns are written with different rotations, whereby the columns thus start in different positions in the bit sequence. The position coding in the horizontal direction is based on the differences between a number of adjacent columns. The position coding in the vertical direction is built up in a corresponding way and is thus based on the differences between a number of adjacent lines. Since the position coding is described in WO Ol / 26032 and is not needed for the understanding of how to code the additional information, it is not described in more detail here. Suppose now that you create a bit sequence which is made up of two annular sections, each of which has the above-mentioned property that if you take out a sub-sequence of predetermined length, its position in the annular section is unambiguous. determined. Assume further that these two annular sections have a sub-sequence which is common and which thus connects the sections to an eight-shaped bit sequence. Then you can encode a piece of additional information by defining that sub-sequences belonging to the first section represent additional information in the form of a first value, for example a zero, and sub-sequences belonging to the second section represent additional information in the form of a second value , for example a one. However, this means that you can encode fewer positions using the bit sequence because the sub-sequences in the second section encode the same positions in the bit sequence as the sub-sequences in the first section. For example, when a field on a physical page with a position coding pattern is to be coded as activated, i.e. with a first value of the additional information, the bit sequences are written in the columns and rows so that the first section of the bit sequence is repeated until the field which must be activated nose. Then a transition to the second section takes place as soon as the printout of the bit sequence reaches the sub-sequence that is common to the first and the second section. Then the second section is repeated until the end of the field to be activated is reached, whereby the transition to the first section takes place as soon as the common sub-sequence is reached. Since the bit sequences are written with different rotation in the different columns, the common subsequence will not be reached exactly at the same time in all columns. Therefore, the boundaries of the fields will be slightly uneven. To get away from this problem, however, it can be defined that only the area that is coded in both the horizontal and vertical directions with the second section of the bit sequence defines an activated field. The decoding takes place in the manner described in WO 01/26032, but when a position of a sub-sequence in the bit sequence is to be determined, it is also determined to which section of the bit sequence the sub-sequence belongs and thus the value of the additional the information.

The coding and decoding can take place by the same means as described above in connection with coding and decoding of additional information by means of a second parameter.

Instead of a bit sequence, a speech sequence with a different base can be used. Furthermore, more loops or sections can be provided in the speech sequence so that more values of the additional information can be coded.

Thus, when this position coding pattern is applied to a product, a product is provided which is provided with a position coding pattern which encodes coordinates of a plurality of points on the product on the basis of a speech sequence having the property that a sub-sequence of the speech sequence of predetermined length has a unique determined position in the speech sequence, this speech sequence having at least a first and a second section, each having the above-mentioned property and wherein areas with position coding patterns on the product have different properties depending on whether they are coded with the first or the second The section of the speech sequence. f m1. ...... = .. ';

Claims (39)

10 15 20 25 30 h) (fl 520 045 Amended claims 28 PATENT CLAIMS Product provided with a coding pattern, which encodes position information in the form of coordinates of a plurality of points on the product by means of a plurality of markings belonging to each point, the markings having a first parameter which varies for coding the position information, characterized because the markers have a second parameter that varies for encoding additional information in the encoding pattern. The product of claim 1, wherein the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. The product of claim 1 or 2, wherein the additional information is additional position information. A product according to claim 1 or 2, wherein the additional information is information other than position information. A product according to any one of claims 1, 2 and 4, wherein the additional information defines at least two different areas of the coding pattern. The product of claim 5, wherein the additional information defines how coordinates recorded from said at least two different areas are to be processed. A product according to any one of claims 1, 2 and 4, wherein the further information defines whether a predetermined area in the coding pattern is activated or not. A product according to any one of the preceding claims, wherein the coding pattern is divided into a plurality of cells, each comprising at least two markings, and wherein the further formation consists of a cell value encoded by said at least two markings for each cell. (Il l0 15 20 25 30 LU Uï 520 045 Amended claims 29 The product of claim 8, wherein the cells comprise fewer markings than said plurality of markings belonging to each point. The product of claim 8 or 9, wherein each label has one of at least two predetermined values for the second parameter and wherein each cell comprises at least one label with each of the predetermined values. The product of any of claims 8-10, wherein the coding pattern comprises a first region and a second region, and wherein the cells in the first region have a first cell value and the cells in the second region have a second cell value. The product of claim 11, wherein a boundary region between the first region and the second region comprises cells with the first cell value and cells with the second cell value. A method of an encoding apparatus for encoding a coding pattern which encodes position information in the form of coordinates of a plurality of points by means of a plurality of markings associated with each point, comprising the step of assigning to each marking in the coding pattern for marking the position information one of at least two predetermined values for a first parameter, characterized by the step of assigning to each mark one of at least two predetermined values for a second parameter for coding additional information in the coding pattern. The method of claim 13, wherein the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. A method according to claim 13 or 14, comprising the step of assigning marks belonging to points within a first coordinate range, values for the second (Il 10 15 20 25 30 LU U '| 520 045 Modified claim 30 parameter which makes it possible to from the markings detect the extent of the first coordinate area in the coding pattern. A method according to claim 13 or 14, comprising the step of marking a predetermined area of the coding pattern as activated by assigning marks belonging to points within the predetermined area a predetermined value for the second parameter. The method of any of claims 13-16, further comprising the steps of dividing the coding pattern into cells, each comprising at least two marks, and assigning to each cell a cell value constituting the additional information, the step of assigning each selection a value for the second parameter occurs depending on the cell value. The method of claim 17, wherein the markers within each cell are assigned values such that each cell contains at least one marker with each of the predetermined values. The method of any of claims 13-18, further comprising the step of providing a coding pattern product by applying the coding pattern with markings having the assigned values for the first and second parameters of a product. A computer program, which comprises instructions for causing a computer to perform a method according to any one of claims 13-19. An apparatus for encoding a coding pattern which encodes position information in the form of coordinates of a plurality of points by means of a plurality of markings associated with each point, the apparatus comprising processing means for determining a value of a first parameter for each mark and a value for a second parameter for each selection and a memory for storing the values of the markings for the first and second parameters. 10 15 20 25 30 LU LH 520 045 Amended claims 31 The device of claim 21, wherein the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. Device according to claim 21 or 22, wherein the processing means are arranged to assign marks belonging to points within a first coordinate area, values for the second parameter which make it possible to detect from the markings the extent of the first coordinate area in the coding pattern. The apparatus of claim 21 or 22, wherein the processing means is arranged to mark a predetermined area of the coding pattern as activated by assigning markings belonging to points within the predetermined area a predetermined value for the second parameter. The apparatus of any of claims 21-24, wherein the processing means is further arranged to divide the coding pattern into cells, each comprising at least two markings, and to assign to each cell a cell value constituting the additional information, the step of assigning each selection a value for the second parameter occurs depending on the cell value. The device of claim 25, wherein the markings within each cell are assigned values such that each cell contains at least one marker with each of the predetermined values. A method of decoding, in a decoding device, a coding pattern which encodes position information in the form of coordinates of a plurality of points on a product by means of a plurality of markings associated with each point, comprising the steps of receiving a digital representation. of the coding pattern, to decode the position information by means of the value of the first parameter for at least some of the markings in the digit h) Ul 520 045 Amended claims 32 speak the representation characterized by the step of further decoding information from the coding pattern based on the value of a second parameter for at least some of the markings in the digital representation. The method of claim 27, wherein the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. The method of claim 27 or 28, further comprising the step of determining how coordinates recorded from the coding pattern are to be processed based on the value of the second parameter for at least some of the marks in the digital representation. The method of claim 27 or 28, further comprising the step of determining whether or not a predefined area in the coding pattern is activated based on the value of the second parameter for markings belonging to points in the area. The method of any of claims 27-30, further comprising the step of dividing the coding pattern into cells based on the position information and determining a cell value for each cell based on the value of the other parameter for the cell markings. The method of claim 31, further comprising the step of processing the position information in dependence on the cell values of the corresponding cells. A computer program, comprising instructions for causing a computer to perform a procedure according to any of claims 27-32. 34. A device for decoding a coding pattern which encodes position information in the form of coordinates of a plurality of points on a product by means of a plurality of markings belonging to each point, which device comprises processing means arranged to receive a digital representation. of the coding pattern, that DJ (II 520 045 Amended Claim 33 decodes the position information by means of the value of the first parameter for at least some of the markings in the digital representation characterized in that the processing means are further arranged to decode further information from the coding pattern based on the value of a second parameter for at least some of the markings in the digital representation. The device of claim 34, wherein the first and second parameters are any of the following pairs: location and size; location and color; size and location; size and shape; size and color; shape and location; shape and color; shape and size; color and location; color and size; and color and shape. An apparatus according to claim 34 or 35, wherein the processing means is arranged to determine how coordinates recorded from the coding pattern are to be processed on the basis of the value of the second parameter for at least some of the markings in the digital representation. . An apparatus according to claim 35 or 36, wherein the processing means is arranged to determine whether or not a predefined area in the coding pattern is activated on the basis of the value of the second parameter for markings belonging to points in the area. An apparatus according to any one of claims 35-37, wherein the processing means is arranged to divide the coding pattern into cells on the basis of the position information and to determine a cell value for each cell on the basis of the value of the other parameter for the cell markings. The device of claim 38, wherein the processing means is arranged to process the position information depending on the cell values of the corresponding cells. Pub1.bild = fig 3